This official introduction is a gateway to ITIL. It explains the basic concept of IT Service Management (ITSM) and the place of ITIL, introducing the new lifecycle model, which puts into context all the familiar ITIL processes from the earlier books. It also serves to illuminate the background of thr new ITIL structure.This title introduces ITSM and ITIL, explains why the service lifecycle approach is best practice in today's ITSM, and makes a persuasive case for change.After showing high level process models, it takes the reader through the main principles that govern the new version: lifecycle stages, governance and decision making, then the principles behind design and deployment, and operation and optimisation.